Exemplary embodiments of the invention relate to a data glove having tactile feedback at a finger upon interaction of the finger with an interaction element on an infrared touch screen. Exemplary embodiments of the invention further relate to a method for generating tactile feedback at a finger of a data glove upon interaction of the finger with an interaction element on a touch screen.
In the following description a touch screen is generally to be understood as a touch-sensitive surface.
Touch screens are well known and have found their way into many areas of daily life, e.g., operating cash machines. In principle, a distinction is made between two different technologies of touch screens: the resistive touch screens and the capacitive touch screens. There are also technologies that are based thereon such as near-field imaging, acoustic wave or infrared touch screen.
A touch screen, tactile screen, touch-sensitive screen or touch panel is a combined input and output device at which by touching parts of an image, the program sequence of a technical device, in most cases of a computer, can be controlled directly. The technical implementation of the command input is, as it were, invisible for the user and thus creates the impression of directly controlling a computer via fingertip.
Touchscreens are characterized by simple and flexible operation. They make it possible to directly interact with graphic objects that are presented on the display. This is implemented through touch-sensitive active surfaces that are arranged around graphic objects. The graphic objects serve for visual identification of the interaction element. The operating logic underlying the active surfaces normally follows the behavior of physically real operating devices such as, for example, switches or control elements. In this manner, characteristics of almost any input device can be simulated.
However, operating via touchscreens is often not as efficient as with physically real operating devices, for example, a keyboard. A reason for this is the missing feedback of the touchscreen. This has a double effect since tactile feedback during input actions via physically real input devices, on the one hand, helps identifying the correct input device and, on the other, provides feedback about the success of the performed operating action. While in the case of a physically real keyboard, identification can take place not only through the usual identification via the eye, but in addition also by feeling edges, surfaces and gaps via the tactile sense of the finger tips, the latter is not possible in the case of a virtual keyboard. When inputting through a virtual keyboard, the visual sensory channel is therefore more challenged, as a result of which only reduced visual capacities are available for further actions. Furthermore, this can result in restricted performance of the operator if he/she expects feedback but does not receive it.
Also, when performing the actual operating action, the virtual keyboard offers no tactile feedback. The operator receives feedback via the receptors of the finger tips whether the screen has been touched. However, this feedback is not necessarily associated with the success of the operating action. For this, feedback has to be generated visually again. In contrast, in the case of a physically real keyboard, the operator, during the input action, has first to overcome the pressure point of the spring and subsequently has to carry out a translational actuating movement. The operator receives feedback on the success of his operating action through the key stop point which limits the translational actuating movement.
This means a physically real keyboard provides tactile feedback to the operator both before and after an input action, as a result of which the visual sensory channel of the operator is relieved. Thus, the input action can be performed more efficiently than with a virtual keyboard.
It is known that in the case of a touchscreen, the finger position on the touchscreen can be detected. Thus, if an input action is performed on the screen by the operator, first the infrared touch frame detects on the screen the relative position of the finger that touches the touchscreen or is situated in close proximity above the touchscreen. If this position coincides with that of an interaction element, the intended operating functionality is performed.
German patent document DE 10 2005 011 432 A1 discloses a virtual reality system in which individual fingers of a data glove can be identified by means of a camera system. German patent document DE 20 2005 019 953 U1 discloses a data glove having feedback.
Exemplary embodiments of the invention are directed to a data glove by means of which the operator receives tactile feedback upon successful completion of an operating action on an infrared touchscreen.
Further, exemplary embodiments of the invention are directed to a method by means of which upon successful completion of an operating action on a touchscreen, tactile feedback is generated at a finger of a data glove that interacts with a touch screen.
According to the invention, the stimulators for generating tactile feedback are attached to the finger-receiving elements of the data glove. The data glove according to the invention has means for identifying the finger interacting with the infrared touchscreen and a signal generator for exciting the stimulator of the interacting finger upon successful actuation of an interaction element on the infrared touchscreen.
According to method described in the invention, the finger of a data glove, which finger interacts with a touch screen, is identified. Upon successful actuation of an interaction element on the touchscreen, a tactile stimulus is generated at the interacting finger.
Here, the tactile feedback at the finger that is identified as the one that interacts with the touchscreen (selective feedback) is advantageously generated by a stimulator for generating a vibration stimulus, a mechanical, electrical or thermal stimulus. Due to the rapid response characteristic of the stimulator and the good perceptibility and the physical comfort of the operator, the vibrating stimulus is preferred over other types of stimuli (pressure stimuli, thermal stimuli, electrical stimuli).
Identifying the interacting finger can take place, e.g., by means of a plurality of cameras, according to the disclosure of German patent document DE 10 2005 011 432 A1.
In an advantageous configuration of the invention, the touchscreen is an infrared touchscreen. In this case, infrared technology is used for detecting the finger interacting on the infrared touchscreen. Advantageously, infrared photodetectors, e.g., infrared phototransistors or infrared photodiodes, which are able to detect the infrared rays emitted from an infrared touchscreen, are attached in the region of the fingertips of the data glove.
The photocurrents of the infrared photodetectors used for detection are evaluated, and the infrared photodetector having the maximum photocurrent is determined. The evaluation is advantageously carried out by means of a microcontroller, e.g., by means of an integrated comparator. Since the infrared grid of the infrared touchscreen becomes weaker with increasing distance from the display, the infrared photodetector having the maximum photocurrent is closer to the screen surface of the touchscreen compared with the other infrared photodetectors. Since each finger-receiving element of the data glove, advantageously in the region of the fingertips, is associated with an infrared photodetector, the finger interacting with the touchscreen thus can be determined.
Upon successful actuation of an interaction element on the infrared touchscreen, the infrared touchscreen sends an electrical signal to the data glove. The connection between the infrared touchscreen and the data glove is established by means of known interfaces, e.g., serial interfaces.
In a particular embodiment of the invention, transmitting the electrical signal to the data glove triggers the identification of the finger interacting with the infrared touchscreen. In other words, only after the infrared touchscreen registers a successful actuation of an interaction element and therefore transmits a corresponding trigger signal to the data glove, the identification of that finger is initiated in the data glove that interacts with the touch screen and thereby has triggered the successful actuation of the interaction element.
The trigger signal can be a specific electrical signal in which further information is contained. For example, it can contain whether the successful actuation of the interaction element is a particular operating functionality such as a “lift off” event (=the interacting finger leaves the active screen surface) or a “touch” event (=the interacting finger touches an active screen surface of the touchscreen for identifying operating elements on the touchscreen). Another example would be a “drag” event (=the interacting finger moves from the outside into an active screen surface of the touchscreen).
After a successful actuation of the interaction element on the infrared touchscreen has been registered and transmitted to the data glove and after the corresponding interacting finger has been identified, a signal is sent to the stimulator of the corresponding finger so as to generate a tactile stimulus. It is possible here that the signal sent to the stimulator is a specific signal that depends on the trigger signal sent by the data glove according to the operating functionality. Thus, it is possible, depending on the operating functionality, to transmit a corresponding feedback to the interacting finger, which feedback varies, e.g., in terms of vibration duration, vibration frequency (strength) and amplitude curve.
The display quality of the infrared touchscreen is not negatively influenced in any way by the sensor system used; the transmission degree is not reduced. By decoupling the device generating the feedback (stimulator on the data glove) from the touchscreen, no vibration-induced blurry effect occurs on the touchscreen.